Waterproofed paper container.



1E. 0. HAWKINS.

WATERPROOFED PAPER CONTAINER. APPLICATION FILED JULY 6.1918.

LWLMQ Patented Apr. 29,1919.

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Application filed J1 uly 6, 1918.

To all whom it may concern:

Be it known that l, EDWIN C. HAWKINS, a

citizen of the United States, residing at Noblesville, in the county of.Hamilton and State of Indiana, have invented a new and awhile in storageor transit, but must be kept tree from moisture, because they would bespoiled if permitted to become wet or even damp. Containers of themailing tube type have not heretofore been suitable for such articles,for attempts ,p efi'ectively to waterproof such containers, againstsubmergence for instance, had not been successful. This was largelybecause of the joints in these containers, both between the adjacentturns oi. the helical winding and between the body of the container andits end pieces, which joints gave water ready access. to the edges ofthe paper layers so that it could soak edgewise through them. By reasonof the structure of the paper used for such tubes, such as strawboardand test-board, this is much easier than soaking transverselytherethrough.

By my present invention, 1 provide a paper container which is not onlyimpervious to water transversely, but one in which the joints both inthe body of the container and between such body and the end pieces arewaterproof, so that access of water to the edges of the paper layers isprevented. In order to do this, I cover the surface of the papercontainer and span such joints by a vulcanized rubber film, which isapplied as a solution of rubber in a. volatile solvent,

preferably in two coats with evaporation of the solvent between theapplication of the two coats, and is vulcanized in position after thefinal evaporation of the solvent. The process of waterproofing thesecontainers is claimed inmy co-pending application Ser. No. 243686 ofeven. filing date here-- with.

pec1fication of Letters Patent.

Patented Apr. 1919.

serial no. ace s85.

The accompanying drawing illustrates my invention.

Figure 1 is a perspective view of a waterproof paper container embodyingmy invention; and Fig. 2 is a partial longitudinal. section through sucha paper container, of somewhat difi'erent form and one somewhat largerscale, and with the thickness of the walls and the rubber coatingmagnified, to show more clearly how the rubber coating overlaps thejoints.

The body of the container comprises a plurality of layers 10, ofsuitable paper such as strawboard or test-board, wound helically uponone another to form a tube, in the usual manner of mailing tubes. Thejoints ll of the respective layers break with one another, so thatbeneath such joints of each layer there is a jointless surface of theadjacent layer. The end members of the tube fit over or within the tube,as desired, in the latter case some of the outer layers of the tube,near the end preferably being folded in upon themselves so as to leaveno raw edges exposed. The end pieces may be of material similar to thatof the tube, as is thepermanently closing end disk 12 of Fig. 2; or maybe of metal, as are the end piece 13 of Fig. 2 and the end bands 1% and15 of Fig. 1. If of metal, they may be parts of closing end caps, as inthe band 14:; or they may or may not be provided with internal orexternal screw threads, as are the end piece 13 and the end band 15, forreceiving a detachable closing piece, such as the end cap 16 of Fig. 1.In the particular containers shown, a paper closing disk is showninserted in one end of the container body of Fig. 2, and metal end capsor bands are shown encircling the other end of the con tainer in thatfigure and both ends of the container in Fig. 1; but these are merelyillustrative arrangements, to show both an inserted and an encirclingend piece and both a paper and a metal end piece, and neitherarrangement is essential. The paper container itself is old, and maytake various forms; per se, it is not my invention.

In order to water-proof the container, ll first apply to one or bothsurfacesas illustrated, to the outside surface-21. solution of rubber insome volatile solvent, such as benzol, gasolene, carbon tetrachlorid, orcarbon bisulfid; particularly I spread this solution over the helicaljoints 11 between the adjacent edges of successive turns of the paperlayer forming the surface being coated and over the joints 17 betweenthe body of the container and the end pieces 12, 13, 14, or 15. When theend pieces are paper, such as the disk 12, I apply the solution over thecorresponding surface thereof as well as over the entire surface of thetube; and when they are metal, such as the end piece 13 and the endbands 14 and 15, I apply the solution over the joints 17 and part way upon to the metal. Preferably I apply this solution with a brush, brushingin both directions; and particularly I brush in both directions over thehelical joints 11 so as to cover both raw edges at such joints. I

find the best results are obtained if the brushing over the joints 11 isdone obliquely to such oints, as by brushing in planes perpendicular tothe tube axis. After the solution has been applied, the solvent ispermitted to evaporate, preferably in a current of hot air to expeditethe evaporation. This leaves a thin film of rubber on' the surface onwhich the solution has been applied and spanning the joints 11 and 17.This first coat acts as a filler, to some extent, to fill the pores ofthe paper. After the solvent of the first coat has evaporated, a secondcoat of the rubber solution is applied over the first coat, care beintaken as before to cover the joints 11 an 17; and then the solvent ofthis second coat is allowed to evaporate. This leaves a second rubberfilm superposed upon and coalescing with the first, to form a rubbercoating 18 covering the surface and spanning the joints 11 and 17. Thenthis rubber coating 18, if obtained from a non-vulcanizing solvent suchas gasolene, benzol, or carbon tetrachlorid, is exposed to a suitablevulcanizer, such as sulfur chlorid. The vulcanizer may be applied with abrush as a liquid, or the rubber coating may be exposed to the fumes ofthe vulcanizer. The vulcanizing process is continued until the desiredquality of rubber in the coating is obtained. .However, if the rubbersolvent used is itself a vulcanizer, as is carbon bisulfid,vulcanization is produced thereby, and no other vulcanizer "need beapplied.

The rubber solution and the vulcanizer may be applied by hand or bymachinery, one machine for applying it to open-ended tubular containersbeing shown in the copending application of Charles B. Macy, Ser. No.M3629, of even filing date herewith.

The container which is thus produced is substantially water-proof underrigid tests.

It may be submerged inwater for considerable lengths of time and underconsiderable pressure, without any seepage of moisture through 1t. Itmay therefore be used for storing and transporting materials which mustbe kept dry but which are in danger of exposure to moisture in storageor transit; such as gun shells, shell timers, medical and surgical andhospital supplies, and also many other articles useful in both war andpeace. The container may also be used as the permanent casing of manyarticles, such for instance as hand grenades, the contents of which mustbe kept dry. By applying the rubber solution to the inside surfaceinstead of to the outside surface, the container is protected frominternal moisture, so that it may be'used as a holder for such liquidsas do not re-act upon or dissolve rubber.

I claim as my invention:

1. A water-proof container, comprising a paper container coated with avulcanized rubber film which was applied in solution in a plurality ofcoats and vulcanized in posi- 85 tion.

2. A water-proof container, comprising a paper container coated with avulcanized rubber film which was applied in solution and vulcanized inosition.

3. A water-proo container, comprising a paper container of the mailingtube type with helical joints in its surface, and a vulcanized film ofrubber spanning such helical joints and applied in solution in aplurality of coats and vulcanized in position.

l. A water-proof container, comprising a paper container of themailingtube type with helical joints in its surface, and a vulcanized film ofrubber spanning such helical joints and applied in solution andvulcanized in position. i

5. A water-proof container, comprising a tubublar body of the mailingtube type with helical joints in its surface, separate end pieces at theends of such tubular body with joints between such end' pieces and body,and a vulcanized film of rubber spanning said helical joints and thejoints between such end pieces and body, said film of rubber beingapplied in solution in a plurality of coats and vulcanized in position.

6. A water-proof container, comprising a tubular body of the mailin tubetype with helical joints in its sur ace, separate end pieces at the endsof such tubular body with joints between such end pieces and body, and avulcanized film of rubber spanning said helical joints and the jointsbetween such end pieces and body, said film of rubber being applied insolution and vulcanized in position.

7. A water-proof container, comprising a tubular body, separate endpieces at the ends of such tubular body with joints between such endpieces and body, and a vulcanized film of rubber spanning said jointsbetween such .endpieces and body, said film of rubber being applied insolution in a 130 ice I aoneeo LE3 plurality of coats and vulcanized inposiof rubber being applied in solution and vultion. canized inposition. 10 8. A water-proof container, comprising a In Witnesswhereof, I have hereunto set tubular body, separate end pieces at the myhand at Indianapolis, Indiana, this 21st 5 ends of such tubular bodywith joints beday of June, A. D. one thousand nine huntween such endpieces and body, and a vuldred and eighteen. canized film of rubberspannin said joints between such end pieces and b0 y, said film EDWIN C.HAWKINS.

